Optimal design of grid-connected rooftop PV systems: An overview and a new approach with application to educational buildings in arid climates

Abstract

Recently, rooftop photovoltaic (PV) systems are widely deployed due to their technical, economic and socio-environmental benefits. This paper presents a new design approach, which combines spatial analysis with techno-economic optimization for a robust design and evaluation of the technical and economic potential of grid-connected rooftop PV (GCR-PV) systems, focusing on educational buildings in arid environments. A university campus in Ouargla province in Algeria is selected as a test-bed in this work. The main objectives of this work are to reduce the cost of energy (COE), grid dependency and CO2 emissions, and even contribute to limit grid blackouts in the building location. Ecotect software, ArcGIS, and HOMER optimizer were therefore used to achieve the contributions of this work. The findings reveal that 60% of the overall roof area is optimally suitable for hosting PV panels. Considering only this optimal area, multi-crystalline PV panels with an inclination of 17° yield the highest annual electricity output (2333.11 MWh/year). Based on this configuration, a sensitivity analysis is then performed to study the effects of feed-in tariffs (FITs) and the cost of components in the system outcomes. It is observed that with FITs less than those applied to large-scale PV projects in Algeria (0.11 $/kWh), the analyzed GCR-PV system has fulfilled high self-sufficiency, reaching grid parity (COE 0.043 $/kWh) and exporting significant amounts of electricity to the grid. Accordingly, the feasibility of the developed approach and the techno-economic viability of the GCR-PV system are both demonstrated.